🐛 Update: Added support for the 'find' command in settings.local.json. Enhanced logging for various modules, including initialization and performance metrics. Improved SQLite database optimization and ensured better tracking of user interactions and system processes. 📚

network-visualization/node_modules/map-stream/index.js

@@ -0,0 +1,145 @@
+//filter will reemit the data if cb(err,pass) pass is truthy
+
+// reduce is more tricky
+// maybe we want to group the reductions or emit progress updates occasionally
+// the most basic reduce just emits one 'data' event after it has recieved 'end'
+
+
+var Stream = require('stream').Stream
+
+
+//create an event stream and apply function to each .write
+//emitting each response as data
+//unless it's an empty callback
+
+module.exports = function (mapper, opts) {
+
+  var stream = new Stream()
+    , self = this
+    , inputs = 0
+    , outputs = 0
+    , ended = false
+    , paused = false
+    , destroyed = false
+    , lastWritten = 0
+    , inNext = false
+
+  this.opts = opts || {};
+  var errorEventName = this.opts.failures ? 'failure' : 'error';
+
+  // Items that are not ready to be written yet (because they would come out of
+  // order) get stuck in a queue for later.
+  var writeQueue = {}
+
+  stream.writable = true
+  stream.readable = true
+
+  function queueData (data, number) {
+    var nextToWrite = lastWritten + 1
+
+    if (number === nextToWrite) {
+      // If it's next, and its not undefined write it
+      if (data !== undefined) {
+        stream.emit.apply(stream, ['data', data])
+      }
+      lastWritten ++
+      nextToWrite ++
+    } else {
+      // Otherwise queue it for later.
+      writeQueue[number] = data
+    }
+
+    // If the next value is in the queue, write it
+    if (writeQueue.hasOwnProperty(nextToWrite)) {
+      var dataToWrite = writeQueue[nextToWrite]
+      delete writeQueue[nextToWrite]
+      return queueData(dataToWrite, nextToWrite)
+    }
+
+    outputs ++
+    if(inputs === outputs) {
+      if(paused) paused = false, stream.emit('drain') //written all the incoming events
+      if(ended) end()
+    }
+  }
+
+  function next (err, data, number) {
+    if(destroyed) return
+    inNext = true
+
+    if (!err || self.opts.failures) {
+      queueData(data, number)
+    }
+
+    if (err) {
+      stream.emit.apply(stream, [ errorEventName, err ]);
+    }
+
+    inNext = false;
+  }
+
+  // Wrap the mapper function by calling its callback with the order number of
+  // the item in the stream.
+  function wrappedMapper (input, number, callback) {
+    return mapper.call(null, input, function(err, data){
+      callback(err, data, number)
+    })
+  }
+
+  stream.write = function (data) {
+    if(ended) throw new Error('map stream is not writable')
+    inNext = false
+    inputs ++
+
+    try {
+      //catch sync errors and handle them like async errors
+      var written = wrappedMapper(data, inputs, next)
+      paused = (written === false)
+      return !paused
+    } catch (err) {
+      //if the callback has been called syncronously, and the error
+      //has occured in an listener, throw it again.
+      if(inNext)
+        throw err
+      next(err)
+      return !paused
+    }
+  }
+
+  function end (data) {
+    //if end was called with args, write it, 
+    ended = true //write will emit 'end' if ended is true
+    stream.writable = false
+    if(data !== undefined) {
+      return queueData(data, inputs)
+    } else if (inputs == outputs) { //wait for processing 
+      stream.readable = false, stream.emit('end'), stream.destroy() 
+    }
+  }
+
+  stream.end = function (data) {
+    if(ended) return
+    end()
+  }
+
+  stream.destroy = function () {
+    ended = destroyed = true
+    stream.writable = stream.readable = paused = false
+    process.nextTick(function () {
+      stream.emit('close')
+    })
+  }
+  stream.pause = function () {
+    paused = true
+  }
+
+  stream.resume = function () {
+    paused = false
+  }
+
+  return stream
+}
+
+
+
+